A/N: I know Chat seems a bit dark in this, but that's the point. He's living his worst fear, and that's partially that he loses Marinette and partially that he'd let grief make him into a bad person, kinda like his dad had let his grief over his missing wife make him cold and distant and kind of a jerk (a lot of a jerk). And the overdramatics of the vision are intentionally so. Adrien's brain is formulating this nightmare, and he's an anime nerd. Any dream sequences of his are bound to be kinda over the top. Anyway, I know that dark and serious isn't my usual wheelhouse, but I'm giving it a go, so I hope you enjoy! Onwards and upwards!

The akuma was calling herself Frightmare. Her power was inflicting realistic hallucinations of people's worst fears.

Dressed in all black with hints of dark plum, she wore a long gown reminiscent of Morticia Addams that fell past her feet from where she hovered in the air on batlike wings. Maleficent-style horns curled from her temples, face framed by long purple hair. She was grinning manically, the points of her fangs glinting in the dim light, throwing nightmare sand left and right, summoned in her hands, swirling around the points of her clawlike black nails.

Apparently, she'd been mocked for being petrified of a few jump-scares in a horror film and in her angry embarrassment, got akumatized. Chat Noir thought that the akuma must be in her skull necklace, but her heavy cover fire had prevented him from getting close enough to test that theory.

The situation didn't look great: people everywhere convulsing on the ground or curled up tightly into balls screaming in terror or muttering to themselves. Various states of unpleasant-looking catatonia.

Ladybug hadn't showed up yet and Chat Noir was fighting hard to make up the difference until she could arrive. Ladybug, currently Marinette Dupain-Cheng, was trying to sneak into the alley to transform, but the chaos from the wild shots of nightmare sand made it hard to get out of the line of fire. She was currently dodging random bursts of magic with an annoyed grimace, creeping steadily closer to cover so she could get out there and help fix this mess.

Chat rolled out of the way of a blast and popped up into a crouch, catching movement of pink and black from the corner of his eye. Marinette. His heart sped into a panic to see her trying to avoid the magic. His Princess was in danger!

Unfortunately, the akuma saw his gaze dart to her and noticed his alarm. Smirking, she called, "Aww, how cute. The kitty has a favorite civilian. How about I make you watch her suffer her worst fear?" She drew back her hand, a ball of inky blue-black nightmare sand coiling into a ball in her palm.

"No!" he screamed at Frightmare, running to Marinette to pull her out of there, only to miss the fact that the akuma was aiming for him, not his friend. He just barely dodged in time. So threatening Marinette was a diversion, then.

"Chat!" Marinette yelled, reaching towards him, face etched deeply with worry not for herself, but for him. Why did she always have to think of him first? She needed to get to safety!

"Ooh, first name basis! How juicy," Frightmare cooed. "She must be a pretty close friend, huh, Chat Noir? I will enjoy trapping her in a world of fear. Your expression seeing her in pain is gonna be priceless," she cackled.

In the real world, she fired a blast of magic at Chat after feinting at Marinette and it hit him square in the face, knocking him down in a haze of indigo smoke, Marinette screaming his name before ducking away to take this chick down. How dare she hurt her kitty! Though she couldn't believe he fell for the same trick twice. Silly cat, always more worried about her than he was about himself. She could take care of herself.

In Chat's mind, he dodged the blast meant to distract him, just barely, but didn't recover in time to save Marinette from the second shot. The akuma shaped the nightmare sand into a jagged point like an arrowhead instead of a ball and flung it at Marinette with aim straight and true, spearing her through the stomach instead of blasting her in the face with sand.

Chat's heart kicked painfully in his chest as his world stuttered to a stop.

No.

No, please God, no.

Not her.

Not his Princess.

Not Marinette.

Marinette's face twisted up in shock and pain, her mouth opening in a cry of agony, head thrown back. In slow motion, she slumped to her knees, hands going to the hole in her stomach as the projectile dissolved into sand. Chat's body moved without him consciously commanding it and he was there to hold her before she could fall all the way to the ground.

Her torso was propped in his lap, legs splayed across the pavement. His arms wrapped around her trembling body tightly, cradling her to his chest. Hers heaved with her erratic, gurgling breaths. Her shirt was soaked through with red, beginning to pool on the ground around Chat's knees. A trickle of it dribbled from the corner of her mouth as she gasped and choked on her own blood.

Frightmare was chortling victoriously. "Oh, look at your face," she crowed. "It was so much sweeter to kill her than trap her in a nightmare. This way, there's no going back even if Ladybug wins this round. Foolproof revenge."

"Why?" Chat hollered, voice cracking.

"Because I hate you, little hero. Did you really think that anything you loved would stay safe from Hawk Moth? It won't end here. He'll destroy everything you care about and make you watch it burn, kitten," Frightmare crooned. "That's a promise straight from the boss man himself."

"He'll pay for this," Chat growled. "And she'll be fine. I can get her to a hospital..."

Frightmare flung her head back in a spiteful laugh. "Sorry to burst your bubble, but no doctor can fix that. And even if they could, I aimed well. The injuries to her spine... even if she lives, she'll never walk again. You think she'll thank you for saving her to live her life in a chair?"

"Ch- Chat," Marinette choked, drawing his gaze to her. "I- I don't wanna die. I don't wanna die."

"You won't, Princess. I'll save you," he swore, brushing her hair from her face with a claw. "We just have to-"

"You can't," she wheezed. "It's... too... late."

Her hand came up to cup his cheek and she gave him a watery smile, teeth stained crimson. He covered her hand with his and opened his mouth to reassure her, but before he could force the words past his lips, her smile dimmed and the light flickered out of her beautiful blue eyes. Her arm went limp and her hand slipped from between his fingers and fell from his face. It hit the ground with a faint thud.

"Marinette?" he breathed, lifting her head with a hand. When he got no response, he croaked louder, "Marinette?!"

Nothing. She was perfectly still, eyes open but unseeing, warmth already fading from her skin. Chat pressed his forehead to hers and let his tears fall on her slackened face. He sobbed brokenly, shoulders shaking, hand buried in her midnight hair. He didn't know how long he stayed like that, clutching her poor body to him, crying over her. Long before he ran out of tears, he heard the akuma tsking behind him.

"Such a shame," she sighed mockingly. "A young life snuffed out too soon. A tragedy, to be certain. And everyone will know it's your fault. How will her parents feel knowing I only killed her because she was the love of your life?"

Chat only glared wordlessly, a snarl on his lips. This thing killed her. It killed Marinette, under Hawk Moth's orders. Screw the rules. Screw the fact that this person under the monster didn't know what they were doing, didn't have a choice. He was going to rip them to pieces and Hawk Moth was next. His grief overwhelmed him so that all he could see was Marinette's beautiful face falling shut like a book as she died in his arms, her blood on his hands.

Red red red red red.

Blood, rage, didn't matter.

It was everywhere.

It was everything.

It was the only color left in a world gone gray without his Princess in it.

He turned his acidic green gaze to the akuma. Pressing a final kiss to Marinette's cheek, he gently laid her down as he stood on unsteady feet. He was off-balance and the world was wrong, but he would see justice done.

"Hawk Moth has a message for you," Frightmare informed him silkily, a lazy grin framed by a glowing purple butterfly. "This Marinette was only the beginning. He won't stop until he has obliterated everything you love. Unless... you surrender your miraculous now. If you're a good boy about it, maybe he'll even use ultimate power to bring back your little girlfriend once he has Ladybug's miraculous, if you help him take it."

"Never," he hissed.

"Come again?" Frightmare spluttered. "She's gone and you're beaten. What do you think you're going to do?"

Chat leapt higher than he'd ever leapt before, ripped the akuma out of the air by the wings, and flung her to the ground with bone-shattering impact. Pouncing on her with claws gouging her shoulders hard enough to draw blood, belt tail lashing in fury, he leaned down to snarl his reply in her face.

"End you."

He lifted her head by the horns and slammed it into the street with a crunch, something in her neck or maybe her skull breaking. Something inside him shrieked in protest, but it was like he couldn't stop his arms. Chat climbed off of her, stepping carelessly on her ruined wings, not looking back as the akuma magic bled from her body and it was just a normal corpse there.

He took Marinette's body and delivered it to her parents without a word, stalking her funeral a few days later so he could properly say goodbye from the shadows. His chest felt hollow and aching, like his heart had been ripped out. His eyes and throat were raw from weeping. Seeing them lay her coffin in the ground made something in him snap and he bolted, looking for something he could break like he felt broken. Chat Cataclysmed the statue of him and his Lady as he yowled his grief to the rainy skies.

After that, days and weeks passed in a blur, as if watching from outside his own body. He only detransformed long enough to feed Plagg and get back to hunting Hawk Moth down, ignoring the Kwami's pleas for him to stop, to go back home to his worried father and Nathalie and the Gorilla. He couldn't stop. Not till he found Hawk Moth and killed him. He had a dogged, near-mindless conviction to one idea, and he operated on autopilot to see it completed.

Ladybug didn't want to work with him anymore after he killed Frightmare, tried to talk to him at first, calm him down, get him to deal with things, but he brushed her off. Then she tried to stop him, too. He left her alone to deal with akumas as he used them to learn about his enemy. The public was terrified of him, but he didn't care.

He came so close a few times, arriving at a lair moments after Hawk Moth had abandoned it. But most of the time, he was chasing his own tail. When he wasn't doing that, he was at Mari's grave, brooding over his failure to protect her, missing her fiercely, hurting so bad he wanted to tear himself to pieces to not have to feel it anymore. But he couldn't. Not until he'd destroyed the man who took her from him.

Months passed, then years, Chat growing more bitter and lonely every day, the pain increasing to an unbearable weight. But still he couldn't stop. Wouldn't ever stop. Not till the day he died.

He'd lost himself. He knew this. But he no longer had enough of his soul left to care.

This was where Chat was at, the deepest point of despair kneeling over Marinette's weathered grave, tracing the letters of her name with a claw and repeating it like liturgy, when the spell broke and he came up from the nightmare with a gasp. His eyes were wild, claws flailing out at nothing.

"Chat Noir!" Ladybug shouted, coming to land by him, white butterfly fluttering away behind her, several people also coming to, including the former akuma. Frightmare was alive and no longer Frightmare. The events of the past few years hadn't happened. None of it had been real.

It still didn't quite register with Chat, who was blinking at the street like he'd never seen it before, looking at Ladybug like she was a stranger.

"Chat?" she repeated, brow furrowed in concern. "Are you alright, minou? What did you see? You... you screamed like the world was ending. Scared me half to death."

"The world did end," he muttered, raking his claws through his hair, fighting down panic.

It was okay. It had been a nightmare. She hadn't been hit. Marinette was okay. All that bad stuff hadn't really happened. He hadn't hurt anyone. She was alive. His Princess was alive.

"What did you see?" Ladybug asked, crouching by him, rubbing his shoulder comfortingly.

"The akuma... it- it got Marinette. It killed her," he told her, beginning to hyperventilate as the images came back to him.

Her shirt she made herself soaked in red red red, blue eyes staring at nothing, her final, gore-streaked smile. Oh God oh God oh God. Her grave, her scream as she fell to the ground, seeing her pierced and falling and falling and falling over and over again in a loop.

"Chat!" Ladybug cried, shaking him gently, hands going to his face, forcing him to look at her. "It's alright. She's alright. She's okay, minou. It's over." She pulled him close and rubbed his back soothingly as he cried into her shoulder, just letting him weep until the third beep, when he pulled back of his own accord, dashing the tears from his eyes.

"Go. You're down to two spots. I'll be okay," he reassured. "I just- I think I need to see her. To prove to myself that it wasn't real, that she's alive."

"Okay, Chat. Just- call me if you ever need to talk. I'll see you tomorrow for patrol."

She swung away and Chat pole vaulted on his baton to Mari's balcony. His heart pounded desperately in his chest, doubt creeping in the corners of his mind. It had felt so real. He remembered her warm blood on his hands and knees. He remembered how it felt like the world shattered apart when he saw her get hit. He remembered losing himself to vengeance as his grief consumed him. He remembered the look in her eyes when she told him it was too late.

Landing on her balcony, he tapped on the trapdoor with attempted patience, striving for a casual appearance as fear thundered down his veins. No need to scare her for no reason. When her head poked up and she greeted him with a nervous smile, his resolve faltered and he crumbled, sweeping her into his arms, startling a surprised squeak out of her as he crushed her to his chest, face buried in her hair as he tried to surround himself with her scent of bread and vanilla and fabric dye- that smelled like home, trying to make an impression of her on his skin through the suit so he could feel her in his arms even when he was alone so he'd never lose her again.

He didn't even realize he was crying until he pulled back to let Marinette breathe and she brushed tears from his cheeks with her fingers, kissing his nose. She cradled his face, foreheads pressed together, murmuring comforting words, telling him that it was okay, she was here with him and she wasn't going anywhere.

"It was awful, Princess," he mumbled into her hair, crushing her against his chest again. He was never ever going to let go of her again. "You were gone, and I was... lost. It was bad. I was bad. I was so angry and afraid and sad and it hurt so much and I was- I did awful things."

"Hey, I'm okay," she reassured, squeezing him tighter. "And even if I wasn't, you'd never be a bad guy, no matter what. I know you, and you have a good heart. You're a genuinely good person- warm and caring and thoughtful and a sappy romantic dork and a great friend to everyone. You're just so full of light and love and it's one of the things about you that made me fall in love with you. I couldn't imagine a world where you went dark side."

"Really?" he sniffled.

"Really," she confirmed. "You're wonderful, and you haven't let circumstances make you cold or hard yet. I mean, from what you've been able to tell me, you have a perfect villain origin story ready to go, and you haven't given into any dark impulses. I have a feeling that you're a hero through and through- unchangeably."

"I don't deserve you, Princess," he chuckled softly. "You always know what to say."

"Pfft. Lies. I fumble for words all the time," she scoffed. "And you deserve a lot better than me, but I'm glad you'll settle anyway because you're a real catch and I'd never find another guy like you."

"Now, I thought you hated liars, Ms. Liar," he teased. "Because you're the best and I love you and I'm lucky that you love a hot mess like me."

"Emphasis on the hot," she deadpanned, and he burst out laughing.

"You don't have any concept of an appropriate time to flirt or not flirt, do you?" he snorted.

"Nope! It's one of my best character traits."

They went back and forth like that for a bit, trying to distract each other from the heaviness that hung over them in the wake of that day's events. Eventually, they settled from sitting up on the bed to cuddling up to each other laying down, and they fell asleep in each other's arms.

Plagg flew out of the ring, turned off the light, and snuck downstairs to scavenge for cheese to eat so he could transform Adrien before Marinette woke up. He spared a fond glance over his tiny shoulder and the smallest of smirks graced his lips as he rolled his eyes and dove through the trapdoor. He cared about both of them more than he'd ever admit.